Given below are four statements (i – iv) regarding human blood circulatory system. (i) Arteries are thick-walled and have narrow lumen as compared to veins. (ii) Angina is acute chest pain when the blood circulation to the brain is reduced. (iii) Persons with blood group AB can donate blood to any person with any blood group under ABO system. (iv) Calcium ions play a very important role in blood clotting. Which two of the above statements are correct?
- (i) and (iv)
- (i) and (ii)
- (ii) and (iii)
- (iii) and (iv)
Answer
(1) (i) and (iv)
Solution
(i) Correct: arteries carry blood under high pressure, so they have thick muscular walls and a narrow lumen compared with veins.
(ii) Incorrect: as per NCERT, angina pectoris is acute chest pain that appears when enough oxygen is not reaching the heart muscle (not the brain).
(iii) Incorrect: AB persons are universal recipients; the universal donor is blood group O.
(iv) Correct: as per NCERT, calcium ions play a very important role in clotting.
∴ (i) and (iv) are correct.
Answer: (1)